1. Field of the Invention
The present invention relates to a semiconductor memory device, and more particularly, to a semiconductor memory device and multi-row address test method that reduces the time it takes to perform the multi-row address test.
2. Description of the Related Art
Demand for mass storage semiconductor memory devices has rapidly increased. As the storage capacity of semiconductor memory devices increases, time for testing semiconductor memory devices also increases. Since test times are related to productivity of semiconductor memory devices, an attempt to reduce test time is continuously being made. Testing to determine whether or not semiconductor memory cells are defective occupies the greatest percentage of time taken to test semiconductor memory devices.
A multi-row address test method is generally used to reduce the time it takes to test whether memory cells are defective by simultaneously enabling a plurality of word lines. The multi-row address test method is more effective to reduce the time it takes to test whether memory cells are defective than that of a test method where word lines are enabled one-by-one.
To increase memory cell yield, a conventional semiconductor memory devices include spare memory cells. When the conventional semiconductor memory devices have defective memory cells, the defective memory cells are generally avoided in favor of spare cells that are also included in the conventional semiconductor memory devices.
In conventional semiconductor memory devices, when defective cells are replaced with spare cells, the multi-row address test method must not enable normal word lines corresponding to those defective cells, each referred to as a repair word line (RWL). In such cases, it would be advantageous for normal word lines, excluding the repair word lines, to be selectively enabled. However, the semiconductor memory device cannot selectively enable or disable word lines. Therefore, it is difficult and time consuming to perform the multi-row address test method when memory cells are defective.